RU2709403C2 - Pipe connection system for connection of two pipe ends, in particular, two pipe ends located in exhaust path of internal combustion engine - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: invention relates to pipe connection system (1) for connection of two pipe ends (2, 3), in particular, two pipe ends located in exhaust path of internal combustion engine, including two axially oriented towards each other and/or spaced from each other end (2, 3) of pipes, which on their outer circumferential surface have each circularly enveloping its convex spherical section (7), wherein these two ends of pipes with their convex spherical sections (7) are placed in connecting pipe (8), covering these ends (2, 3) of pipes on outer side on the overlapping section, so that convex spherical sections (7) adjoin each, radially rounding it, in area (16) adjoining spherical section to inner wall (9) of connecting pipe (8). According to the invention, convex spherical areas (7) in areas (16) of adjoining spherical sections adjoin each along circumferential line (10) and thus with linear adjacency along circumference to inner wall (9) of connecting pipe (8).

EFFECT: technical result is wider functional capabilities.

17 cl, 6 dwg

Description

The invention relates to a pipe connection system for connecting two ends of pipes, in particular two ends of pipes located in the exhaust tract of an internal combustion engine, according to the preamble of claim 1. The invention further relates to the exhaust tract of an internal combustion engine of a vehicle, in particular an industrial vehicle having a pipe connection system, as well as an industrial vehicle having such an exhaust path.

In the pipe connection system in the exhaust gas stream of the internal combustion engine, in particular, the operational thermal expansion of the pipes must be taken into account, due to which the two ends of the pipes with the end faces are displaced to each other. In addition to such axial displacement, angular errors and axial displacements in the joint system may also occur. To compensate for such tolerances, it is generally known that the ends of the pipes mating with each other are oriented in the axial direction and at a distance, and are tightly connected by means of a pipe connecting device that is capable of deformation and / or has the ability to be displaced by relative movements of the ends of the pipes. As such compensating devices for connecting pipes, it is well known, for example, bellows expansion joints or elastomeric expansion joints attached to each of the two pipe ends, in particular silicone rubber expansion joints, or plug-in connections. Such tightly connecting devices for connecting pipes are most often less resistant to high thermal loads that occur in the exhaust tract of the internal combustion engine than the pipes used, so that weak points with the possibility of leaks can form.

A system for joining two ends of pipes is known from EP 2 273 175 B1, the two ends of the pipes being spaced apart by an axial clearance and connected by a connecting pipe in such a way that the connecting pipe is inserted on the inside of each pipe by an axial end section, fitting in both end regions of the pipes. This creates a tight connection with the possibility of thermal expansion and compensating for position tolerances for connecting the ends of the pipes in the exhaust system of the engine. The connecting pipe should here consist of a precipitation hardening alloy. In addition, the outer surfaces of the connecting pipe must have a wear-resistant coating. Such a wear-resistant galvanized coating is also known from EP 2 096 194 A2.

A similar construction having a wear-resistant coating on the outer surface of the connecting pipe is also known from EP 2 154 408 B1.

Such embodiments of internal connecting pipes are also known from DE 10 2010 045 986 A1, but at the same time also external connecting pipes in which the ends of the pipes abut against the inner walls of the connecting pipe in a wide, surface fitting connection. The ends of the pipes on their outer perimeter surface here can each have an annular spherical convex section around them, while the mating regions of the inner walls of the outer connecting pipe have a correspondingly spherical configuration to create a surface abutting connection.

The outer connecting pipe is also known from DE 1 49 11 70 A, which describes a flexible pipe connection in which the cylindrical ends of the pipes are provided with so-called spherical hypersurfaces that are adjacent to the correspondingly spherically formed inner surface of the connecting pipe.

The disadvantage of all these known pipe connection systems is that sometimes they are very laborious to manufacture and install and, in addition, compensation of the position tolerances to the desired extent is impossible.

In contrast, an object of the present invention is to provide a pipe connection system for connecting the ends of two pipes, in particular two pipes located in the exhaust tract of an internal combustion engine, which is relatively simple both in manufacturing technology and in mounting technology, and which It is able to reliably and reliably compensate for position tolerances over a wide range.

This problem is solved using the features of the independent claims. Preferred embodiments are the subject of the dependent claims.

According to claim 1, there is provided a pipe connection system for connecting the ends of two pipes, in particular two pipes located in the exhaust tract of an internal combustion engine, which has two pipes oriented axially to each other and / or remote from each other, each having their outer circumferential surface along an annular envelope of a convex spherical section, and these two ends of the pipes with their convex spherical sections are received in the connecting pipe, covering these pipe ends from the outside to overlapping section, so that the spherical sections are each adjacent to the inner wall of the connecting pipe, radially bending around it, in the area of contact of the spherical section. In accordance with the invention, it is provided that the convex spherical portions abut each to the inner wall of the connecting pipe in the abutment regions of the spherical portions along a circle line and thereby with a fit made in the form of a circumferential line, in particular, fit snugly. This happens when the diameter of the spherical sections is made equal to the inner diameter of the connecting pipe in the coordinated region of the spherical section.

Such only in the form of a circular line does the fit of the convex spherical sections at the ends of the pipes to the inner wall of the connecting pipe allow, on the one hand, to make a sufficiently tight connection between the connecting pipe and the pipe end, and, in addition, allows to compensate for position tolerances to a particularly large extent, such as, for example, angular errors, axial shifts and / or length shifts, since a fit made in the form of a circumferential line while maintaining a tight fit to the inner wall a connecting pipe permits particularly good deflection tube ends with a relatively large angle of rotation. In addition, such a circumferential line fit, in contrast to a surface fit, is less susceptible to a landing overload causing leaks, for example, due to manufacturing tolerances and / or thermally caused inaccuracies during operation. In addition, the pipe connection according to the invention can also be made in a quick and easy-to-install manner with the external connecting pipe and the spherical sections of the pipe ends located in it only in the form of a circumferential line.

The connecting pipe itself can, in principle, have any shape, for example, can be made in the form of a corrugated pipe, if it is only guaranteed that the inner wall of the connecting pipe for the convex spherical sections made in the form of a circumferential line of contact with the inner wall of the connecting pipe is at least in the region the abutment of the spherical sections is made even and round-cylindrical, with an inner diameter of the inner wall substantially corresponding to the linearly adjacent abutment region of the spherical region in. Of course, the outer diameter of the spherical section, which is defined by fitting along the circumferential line to the inner wall of the connecting pipe, corresponds to the mating inner diameter of the inner wall so that a sufficiently tight fitting connection between the convex spherical sections and the inner wall is made, that is, some excess size to create a functionally reliable and gas tight fit with interference fit.

For example, this excess dimension necessary for an interference fit can be obtained by appropriate coating and / or making mating contact surfaces of wear-resistant material. This means that the inner wall of the connecting pipe, at least in the abutment region of the spherical section and / or the outer surface of the spherical section, can be made of wear-resistant material, respectively, can be coated with such a material.

According to one other particularly preferred embodiment, the inner wall of the connecting pipe is everywhere uniform and round-cylindrical, with the same inner diameter everywhere. Such geometry of the inner wall can be made simply and economically.

Moreover, in order to facilitate the entry of spherical sections at the ends of the pipes on both opposite ends of the connecting pipe, a chamfer can also be made, in particular a rounded chamfer.

Especially simple and economical to manufacture is the connecting pipe, which is made in the form of a cylindrical pipe forming the connecting sleeve, which has the same inner and outer diameters everywhere.

According to another particularly preferred embodiment, a catalytic base can be introduced inside the connecting pipe at least in separate areas and / or inside the connecting pipe, for example, on the inner wall of the connecting pipe, at least in some areas a catalytic coating can be provided to clean the exhaust gases and / or contribute to the purification of exhaust gases. It is particularly preferable that the arrangement of the catalytic base and / or the catalytic coating is carried out in at least one section located between the two regions of contact of the spherical sections. Then, in this case, the connecting pipe, respectively, the inner region (e.g., the inner wall) of the connecting pipe with a particularly preferred dual function, simultaneously contributes to the purification of exhaust gases, due to which the efficiency of the purification of exhaust gases as a whole can increase and increase accordingly.

In addition, the connecting pipe can also be provided with a thermally insulating coating on its outer side, at least in separate regions. This helps to prevent unacceptable heat losses and at the same time surface temperatures, so that undesired condensation in the area of the connecting pipe is then impossible. The coating can, in principle, be made any, for example, of an insulating material, but can also be formed, for example, by a separate structural element, which is lined with a connecting pipe. But alternatively, the thermally insulating coating can also be in the form of a firmly adherent coating, for example, in the form of a thermally stable elastomeric coating, for example, a silicone coating.

With respect to compensation of position tolerances, in particular compensation of angular errors, axial shifts and / or length shifts, it has been found to be particularly preferred when at least one of the two convex spherical sections, preferably both convex spherical sections of the pipe connection system of the invention, as seen in longitudinal section, each form a segment of a circle adjacent to the smooth outer side of the end of the pipe, and for this segment of the circle at least one of the following conditions th:

a) the central angle measured from the center of the circle of the circle segment is 90 ° to 120 °, preferably 100 ° to 110 °;

b) the ratio of the segment height to the segment chord defined by the chord is from 1: 3 to 1: 5, preferably from 1: 3.5 to 1: 4.2;

c) the ratio of segment height to radius is from 1: 2 to 1: 3, preferably from 1: 2.4 to 1: 2.7;

d) the ratio of the radius to the chord defined by the circumference of the length of the circle segment is from 1: 1.25 to 1: 1.75, preferably from 1: 1.4 to 1: 1.6, most preferably about 1: 1.15.

The above relations should be understood so that the second named value always corresponds to a multiple of the first named value, that is, for example, with the ratio b) of the segment height to the circle chord, the ratio 1: 3 specifically means that the circle chord has a value equal to three times the segment height. The same applies to relationship data in c) and d), as well as relationship data, which are likely to be mentioned below.

As already indicated, inventive studies have shown that at least one of the above conditions must be satisfied in order to create a design by which position tolerances and high thermal loads can be functionally reliably compensated within large ranges, while, however, particularly good results in With respect to compensation of tolerances, positions in a large range are achieved when all of the above conditions from a) to d) are fulfilled in the aggregate.

Separate named conditions provide the possibility of a functionally reliable and tight fit of convex spherical sections even with large axial shifts or, accordingly, angular errors with the desired fit along the circumferential line to the inner wall of the connecting pipe. In addition, this can also be further facilitated when, according to another particularly preferred embodiment, it is provided that the distance, in the longitudinal section of the pipe joint system, from the contact point of the convex spherical portion in the main pipe joint position to the lead-in edge of the inner wall of the connecting pipe intended for this spherical section, is equal to a maximum of 2.5 times the height of the segment, preferably a maximum of 2.0 times the height of the segment, and at least 1.0 times the height egmenta, preferably at least 1.5 times the height of the segment. In this embodiment, along with relatively large angular errors and axial displacements, axial displacement of the pipe ends inside the outer connecting pipe can also be functionally reliably performed.

In addition, when choosing the dimensions of the pipe as a whole, it turned out to be preferable if the ratio of the radius of the circle segment to the outer diameter of the end of the pipe in the region outside the convex spherical section is from 1: 1.1 to 1: 1.4, preferably from 1: 1.2 to 1: 1.3. This also ensures that the end of the pipe provided with a convex spherical section can be displaced relative to the connecting pipe within relatively large angular ranges.

According to the manufacturing technology, it is particularly preferable if both spherical sections at the ends of the pipes are identical with geometrically the same dimensions, so that, for example, the connecting pipe can be made especially simple and economical, since both ends can be placed on both sides pipes. This reduces the variety of parts and helps reduce manufacturing and storage costs.

At least one of the convex spherical sections, preferably both convex spherical sections of the pipe connection system are made of a single material and / or integrally with the agreed end of the pipe, for example, by appropriate machining, for example, by turning or milling, or by pressure processing. Alternatively, at least one of the convex spherical sections, preferably both convex spherical sections can be made in the form of a separate structural element, which is connected to its coordinated pipe end with a geometric and / or force and / or geometric closure. The latter embodiment has the advantage that the ends of the pipes can be manufactured in substantially the same parts and can be individually provided with the desired spherical sections.

According to a first particularly preferred embodiment, the end of the pipe may have an internal thread into which a convex spherical section can be screwed with a protruding section having a mating external thread adjacent to the spherical section. Alternatively, the end of the pipe may have an external thread onto which a convex spherical section can be screwed onto a protruding section having a mating internal thread adjacent to the spherical section. With such a screw-in solution, a construction is preferred in which the spherical section has at least one tool extension. This extension for the tool can be made, for example, in the form of several external groove gripping recesses as extensions for the tool.

But alternatively to the just described screw-in solution, the spherical section may also have an internal recess and be pressed onto the end of the pipe in the form of an external press-fit structural element. But alternatively, the spherical section may also have a protruding section, through which the spherical section is pressed into the end of the pipe in the form of an internal pressed structural element. Of course, then, in all of the above embodiments, including the protruding portion, the spherical portion protrudes freely from the end of the pipe, so that it can be inserted, respectively, slide it into the connecting pipe.

For a particularly strong connection of the pipe end to the spherical section, it can be provided that they are connected to each other in at least separate areas by means of material closure. Welding and / or soldering is particularly suitable as a material short circuit connection.

The advantages obtained by using the exhaust tract of the invention, respectively, by using an industrial vehicle proposed by the invention, are identical to those advantages that have already been explained previously in connection with the invention of the pipe connection system.

The connected ends of the pipes are preferably formed by adjacent sections of the exhaust manifold, but in principle they can also be formed by one section of the exhaust manifold and a pipe section aligned with the cylinder head, respectively, by any pipelines through which hot media flow, for example, in the area of the connectors with exhaust piping and / or piping to the exhaust turbocharger, to name other possibilities for using the inventive system with of the connections of pipes connected with its preferred application in the exhaust tract of the internal combustion engine.

Below the invention is explained in more detail using the drawings, which show:

figure 1: schematically and as an example, an external view in perspective of the invention proposed by the invention of the pipe connection system;

figure 2: a pipe connection system in accordance with figure 1 in side view;

figure 3: section of the pipe connection system in accordance with figure 2 along the line A-A in the main position, in which both the pipe ends held in the connecting pipe are shown in the main or initial position and lie exactly on one straight line;

figure 4: the image corresponding to figure 3, on which the ends of the pipes no longer lie exactly on one straight line, but have axial shift to be compensated, respectively, the angular error relative to the main position of figure 3;

5: schematically an alternative embodiment comprising a spherical portion having a protruding portion, this protruding portion having an external thread with which it is screwed into the internal thread of the agreed end of the pipe; and

6: an embodiment alternative to FIG. 5, wherein the protruding portion of the spherical portion has an internal thread that is screwed into the mating external thread of the agreed end of the pipe.

Figure 1 schematically and as an example shows an external perspective view of a pipe connection system 1 of the invention proposed by means of which, here, for example, two ends 2, 3 of pipes connected to an exhaust path not shown in detail, also not shown in detail, are connected to each other an internal combustion engine, for example, adjacent sections of an exhaust manifold not shown here in detail.

As this, in particular, is seen in a joint examination of FIG. 2, which shows a side view of FIG. 1, and also FIG. 3, which shows a side view along line AA of FIG. 2, the pipe connection system 1 has here two the central axes 4, 5 on one straight line, axially oriented to each other and spaced apart by the distance of the axial clearance 6 of the end 2, 3 of the pipes, which on their outer circumferential surface each have a convex spherical section 7 in an annular envelope enveloping it.

Both ends 2, 3 of the pipes, which are shown in Fig. 3 in their main position without axial and angular displacement and, thus, being oriented exactly in a straight line with each other, are placed in their connecting spherical sections 7 in the connecting pipe 8, covering the ends 2, 3 pipes from the outside on an overlapping section.

This connecting pipe 8 is here as an example made in the form of a cylindrical pipe having the same inner and outer diameters everywhere, and at the same time has exactly and round cylindrical, having the same inner diameter everywhere the inner wall 9, to which in Figs. 1-3 in the inserted state, two convex spherical sections 7 of the ends 2, 3 of the pipes are adjacent, each along the circumferential line 10, as shown only schematically and by the dashed line in Fig. 1 and only very schematically in Figs. 2 and 3 (there in a two-dimensional projection).

Using this fit along the circumferential line (i.e., made in the form of a circumferential fit line), a relatively large area is created in which the axial and angular shifts of the two ends of the pipes can be functionally reliably perceived with a constantly tight fit connecting the spherical sections 7 with the inner wall 9 of the connecting pipe 8 in a large area, respectively, in a large volume, which is schematically indicated in Fig.4. Specifically, for this, both convex spherical sections, when viewed in longitudinal section (Fig. 3), are preferably made so that they form a segment 12 of the circle adjacent to the smooth outer side 11 of the ends 2, 3 of the pipe, for which, respectively, act on at least one, preferably all of the following conditions:

a) the central angle α measured from the center M of the circle of segment 12 of the circle is from 90 ° to 120 °, preferably from 100 ° to 110 °;

b) the ratio of the height h of the segment to the defined chord of the circumference of the length l of the segment is from 1: 3 to 1: 5, preferably from 1: 3.5 to 1: 4.2;

c) the ratio of segment height h to radius r is from 1: 2 to 1: 3, preferably from 1: 2.4 to 1: 2.7;

d) the ratio of the radius r to the chord circumference defined by the length l of the circle segment is from 1: 1.25 to 1: 1.75, preferably from 1: 1.4 to 1: 1.6, and most preferably about 1: 1.15 ;

e) the distance, shown in FIG. 3 of the longitudinal section of the pipe connection system 1, from the abutment point A (which belongs to the circumferential line 10) of the convex spherical section 7 to the insertion edge 13 of the inner wall 9 of the connecting pipe intended for this spherical section is equal to the maximum 2.5 times the height of the h segment, preferably a maximum of 2.0 times the height of the h segment, and at least 1.0 times the height of the h segment, preferably at least 1.5 times the height of the h segment.

f) the ratio of the radius r of the circle segment to the outer diameter D _{a of the} ends 2, 3 of the pipe in the area outside the convex spherical section is from 1: 1.1 to 1: 1.4, preferably from 1: 1.2 to 1: 1.3 .

As can be seen from the schematic image of figure 3, but there, for purposes of illustration, shown only on the right end of the connecting pipe 8, at least one, preferably on both opposite end sides of the connecting pipe 8 can be provided on the chamfer 14, in particular, as shown, a rounded chamfer 14, which facilitates the entry of the spherical sections 7 at the ends of the pipes into the connecting pipe 8, in particular when the outer diameter of the spherical section 7 is oversized compared to the corresponding Twain consistent internal diameter of the inner wall 9 of the connecting pipe 8.

As soon as it is schematically seen from FIG. 3 and drawn there only by a dashed line, the connecting pipe 8 on its outer side, at least in certain areas, can be provided with a thermally insulating coating 15. It can, for example, be made of insulating, respectively, insulating material .

According to another, particularly preferred embodiment, in particular, in the inner wall portion 7 located between the two adjoining regions 16 of the spherical portions, an exhaust gas purification and / or an exhaust gas purification facilitating coating 18, in particular a catalytically active coating 18, can be provided. Here it is for illustrative purposes depicted exaggeratedly convex.

In addition, both the inner wall 9 and the surface of the spherical sections 7 can be provided with a wear-resistant coating, respectively, be made there with such a wear-resistant coating, for example, by thermal improvement of the alloy.

As shown in the embodiment of FIGS. 1-4, both convex spherical sections 7 at the ends 2, 3 of the pipes can be made identical, essentially with geometrically the same dimensions, and at the same time be the same parts. For this, each convex spherical section 7 can be made, for example, of a single material and / or integrally with the agreed end of the pipe, which, for example, can be carried out by cutting or by pressure.

However, alternatively, as shown by way of example in FIGS. 5 and 6, in each case on the left spherical section 7 there, at least one of the convex spherical sections 7 can also be made as a separate structural element, which can then be connected to its mating end 2 of the pipe with a geometric and / or with power and / or with a geometric circuit.

As shown by way of example in FIG. 5, the pipe end 2 can, for example, have an internal thread 19 into which a convex spherical section 7 can be screwed with a protruding section 21 having a mating external thread 20 adjacent to the spherical section 7. Of course, as a protruding section 21 and the spherical section 7 have, respectively, form here along the inner recess 22, which form a continuation of the hollow end 2 of the pipe.

Alternative to this embodiment of FIG. 5, in one of the similar embodiments, it may also be provided that the protruding portion 21 is pressed into the end of the pipe.

Figure 6 shows one of the alternative embodiments of Figure 5, in which the end of the pipe has an external thread 23, on which the convex spherical section 7 can be screwed up with a protruding internal thread 24, the protruding section 21 adjacent to the spherical section 7.

Then, on the spherical section 7, here specifically on the protruding section 21, which is an integral part of the spherical section 7, for example, an extension 25 for the tool can be provided, for example, in the form of at least one groove gripping recess for screwing the spherical section to the agreed end pipes. Moreover, in addition or alternatively, the extension 25 for the tool can also be performed directly on the spherical section itself, that is, it can be performed not on the protruding section 21 of the spherical section 7.

Alternative to this embodiment of FIG. 6, in one of the similar embodiments, it may also be provided that the hollow spherical section 7 is pressed onto the end of the pipe.

In addition, alternatively or additionally manufactured as a separate structural element, the spherical section 7 can also be connected to the agreed end 2 of the pipe by a material closure connection, for example, welding and / or soldering.

LIST OF REFERENCE NUMBERS

1 Pipe connection system

2 End of pipe

3 End of pipe

4 Central axis

5 Central axis

6 Axial clearance

7 Spherical section

8 connecting pipe

9 Inner wall

10 District line

11 Flat outside

12 Circle Segment

13 Introductory edge

14 Chamfer

15 Thermally insulating coating

16 Adjacent areas of spherical sections

17 Section of the inner wall

18 Catalytically active coating

19 Internal thread

20 Male thread

21 protruding section

22 Internal recess

23 external thread

24 Internal thread

25 Tool extension.

Claims (24)

1. A pipe connection system (1) for connecting two ends (2, 3) of pipes, in particular two ends of pipes located in the exhaust tract of an internal combustion engine, including two pipes oriented in the axial direction to each other and / or spaced apart from each other (2, 3), each having on its outer circumferential surface an annularly enveloping spherical convex section (7), these two pipe ends their convex spherical sections (7) are placed in the connecting pipe (8), covering these ends (2, 3) of the pipes from the outside on the overlapping section, so that the convex spherical sections (7) are adjacent each, radially enveloping it, in the region (16) spherical fit one portion of the inner wall (9) of the connection pipe (8), characterized in that that the convex spherical sections (7) in the adjoining spherical regions (16) abut each along the circumferential line (10) and thereby in the abutment made in the form of a circumferential line against the inner wall (9) of the connecting pipe (8), moreover, inside the connecting pipe (8) at least in the area (17) located between the two regions (16) of the fit of the spherical sections, a catalytic base and / or at least in some areas of the catalytic coating is provided. 2. The pipe connection system according to claim 1, characterized in that the inner wall of the connecting pipe for made in the form of a circumferential line of fit of the convex spherical sections (7) to the inner wall (9) of the connecting pipe (8) at least in the region (16) the fit of the spherical section is made even and circular-cylindrical, with the inner diameter of the inner wall corresponding to the linearly adjacent region (16) of the fit of the spherical section. 3. The pipe connection system according to claim 1 or 2, characterized in that the inner wall (9) of the connecting pipe (8) is made everywhere smooth and circular to everywhere with the same inner diameter. 4. The pipe connection system according to claim 1, characterized in that on both opposite end sides of the connecting pipe (8), a chamfer (14) is provided, in particular a rounded chamfer. 5. The pipe connection system according to claim 1, characterized in that the connecting pipe (8) is a cylindrical pipe having everywhere the same inner and outer diameter. 6. The pipe connection system according to claim 1, characterized in that the connecting pipe (8) is provided with a thermally insulating coating (15) on its outer side at least in certain areas. 7. The pipe connection system according to claim 1, characterized in that at least one of the two convex spherical sections (7), preferably both convex spherical sections of the pipe connection system (1), when viewed in longitudinal section, each form adjacent to the smooth outer side (11) of the end (2, 3) of the pipe to the segment (12) of the circle, while at least one of the following conditions is met: a) the central angle (α) measured from the center (M) of the circle of the segment (12) of the circle is from 90 ° to 120 °, preferably from 100 ° to 110 °; b) the ratio of the height (h) of the segment to the defined chord (l) of the circumference of the segment length is from 1: 3 to 1: 5, preferably from 1: 3.5 to 1: 4.2; c) the ratio of segment height (h) to radius (r) is from 1: 2 to 1: 3, preferably from 1: 2.4 to 1: 2.7; d) the ratio of the radius (r) to the defined chord (l) of the circumference of the length of the circle segment is from 1: 1.25 to 1: 1.75, preferably from 1: 1.4 to 1: 1.6, most preferably about 1: 1.15. 8. The pipe connection system according to claim 7, characterized in that the distance (ü), in the longitudinal section of the pipe connection system (1), from the point (A) of the fit of the convex spherical section (7) in the main pipe connection position to the the spherical portion (7) of the insertion edge (13) of the inner wall (9) of the connecting pipe is equal to a maximum of 2.5 times the height (h) of the segment, preferably a maximum of 2.0 times the height (h) of the segment, and at least 1.0 -fold height (h) of the segment, preferably at least 1.5 times the height (h) of the segment. 9. A pipe connection system according to claim 7, characterized in that the ratio of the radius (r) of the segment (12) of the circle to the outer diameter (D _a ) of the end (2, 3) of the pipe in the region outside the convex spherical section (7) is equal to 1 : 1.1 to 1: 1.4, preferably from 1: 1.2 to 1: 1.3. 10. The pipe connection system according to claim 1, characterized in that both convex spherical sections (7) at the ends (2, 3) of the pipes are made identically, essentially with geometrically the same dimensions. 11. Pipe connection system according to claim 1, characterized in that at least one of the convex spherical sections (7) is made of a single material and / or integrally with the agreed end (2, 3) of the pipe, in particular by cutting or by pressure treatment. 12. The pipe connection system according to claim 1, characterized in that at least one of the convex spherical sections (7) is made in the form of a separate structural element, which is connected to its geometrical end of the pipe (2, 3), and / or with power and / or geometrical closure. 13. A pipe connection system according to claim 12, characterized in that the end (2, 3) of the pipe has an internal thread (19) into which a convex spherical section (7) can be screwed with a protruding section (21) having an external male thread (20) adjacent to the spherical section (7), or that the end (2, 3) of the pipe has an external thread (23) onto which the convex spherical section (7) can be wound with a protruding section (21) having a mating internal thread (24) adjacent to spherical section (7), while it is preferably provided that the spherical section (7) and EET at least one adapter (25) under the tool, in particular some external grooving gripping recesses in the adapter as a tool. 14. A pipe connection system according to claim 12, characterized in that the spherical section (7) has an internal recess and is pressed onto the end (2, 3) of the pipe in the form of an external press-fit structural element, or that the spherical section (7) has a protruding section ( 21), through which the spherical section (7) is pressed into the end (2, 3) of the pipe in the form of an internal pressed structural element. 15. A pipe connection system according to claim 12, characterized in that the region of the spherical section (7) connected to the pipe end (2, 3) is connected to the pipe end (2, 3) in at least separate areas with material closure, in particular welding and / or soldering. 16. The exhaust tract of an internal combustion engine of a vehicle, in particular an industrial vehicle, according to one of the preceding paragraphs. 17. An industrial vehicle having an exhaust tract according to clause 16.

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